top of page

Pec Minor Syndrome Symptoms

Neurogenic Pec Minor Syndrome is when the brachial plexus nerves are compressed by the pectoralis minor muscle within the subcoracoid space of the shoulder.  It is a nerve compression syndrome which is a condition wherein nerves are being compressed or pinched/squeezed by other internal body structures resulting in nerve damage or dysfunction leading to symptoms.  Carpal tunnel syndrome is also a nerve compression syndrome.  The difference is that, with carpal tunnel, one nerve is compressed lower down in the arm by the wrist, and with NPMS, there are several different nerves being compressed up near the shoulder and armpit.  Since the brachial plexus supplies the nerves to the chest, most of the upper back, shoulder, arm, and hand, symptoms can be experienced in any of these places.  In similarity to NTOS, NPMS can cause several different types of symptoms including nerve symptoms, muscle symptoms, and even symptoms that affect blood flow.  NPMS and NTOS have several overlapping symptoms, but they also each have their own distinct symptoms.  The main distinctions between the two syndromes are:  (1) with NTOS alone, neck pain and occipital headaches (headaches in the back of the head) are common whereas you will typically not see those in someone who only has NPMS and (2) with NPMS alone, chest and armpit pain are common whereas you will typically not see those in someone who only has NTOS.  Occasionally, a patient will have venous PMS, in which case they would have symptoms and presentation similar to VTOS which can be found here.

Symptom Features:

  • Majority of patients are female (approx. 60-70%)

  • Most frequently presents in patients ages 20-40, but can & does occur outside of this range

  • Usually presents on 1 side of the body at least initially, and typically the side of the body with the dominant arm is the side to first show symptoms

  • tend to start gradually and worsen over time but sudden onset can also occur

  • can vary throughout the day or from day-to-day in location, type, and severity especially early on in the condition

  • tend to worsen during sleep with many patients having trouble falling asleep, waking up during the night due to symptoms, or having symptoms upon waking in the morning.  Sleeping positions which can exacerbate symptoms are sleeping with the arm overhead, sleeping on the back, and sleeping on the affected side

  • When not in conjunction with NTOS, can range from mild to moderate and typically not as severe with most patients still being able to work and function

  • Some symptoms worsen with certain TOS-aggravating activity such as heavy lifting or heavy use of the arms, pushing or pulling too much weight, repetitive use of the arms, overhead use of the arms, keeping the arm in an outstretched or awkward position for prolonged periods of time, and anything that involves fine motor skills/fine finger movements.  Such activity examples include:

  • driving

  • brushing teeth

  • talking with the phone up to ear

  • brushing, washing, blow drying, or styling hair

  • typing/texting

  • using a mouse

  • vacuuming

  • folding laundry

  • sewing

  • writing

  • throwing

  • playing an instrument such as guitar or violin

armpit pain
side of breast pain
chest pain


  • Pain, tenderness or tightness in the chest along where a bra strap might run or just below the collarbone

  • Pain in the armpit

  • Pain down the side of the breast or chest

  • Pain radiating down into the breast or lower chest

  • Pain in shoulder, arm and/or hand.  Pain can be any type such as dull, sharp, shooting, stabbing, squeezing, aching, burning, electrical zaps

  • Numbness or tingling in shoulder, arm and/or hand.  Most commonly in the pinky and ring fingers, but it can involve any or all the fingers.

  • Hypersensitivity of the skin of the shoulder, arm and/or hand

  • Feeling of fatigue or heaviness in the arm especially when elevated

  • Feeling of hot or cold sensations within the shoulder, arm, and/or hand

  • Temperature and color changes of the hand (cold & bluish purple) or (hot & red) especially when arm is elevated or hanging straight down (Click here to learn more about the role of NPMS in these types of symptoms)

  • Swelling of the hand and/or fingers

  • Loss of hand dexterity such as inability to grip or pinch objects and easily dropping things

  • Enlarged or bulging veins in the arm and/or hand

  • Claw hand (characterized by curved or bent fingers, making the hand appear claw-like)

  • Muscle spasm and twitching in the arm and/or hand

  • Shoulder blade pain (often dull & more muscular in nature)

  • Winged shoulder blade (shoulder blade is prominent & sticks out from the back instead of lying flat)

  • Upper back muscle spasm, tightness, and pain particularly in upper trapezius, rhomboid, levator scapulae, and muscles that surround the shoulder blade

  • Decreased range of motion in the shoulder and arm

woman with shoulder pain

Additional Information Related to the Role of NPMS in Causing Vascular Symptoms

Symptoms related to blood flow changes such as changes in temperature and color and swelling are actually quite common in patients with NTOS and can also be seen in those with NPMS.  These symptoms are often assumed to be caused by Arterial or Venous TOS, but typically, this is not the case.  It’s actually caused by a sympathetic induced vasoconstriction. The sympathetic nervous system controls the blood vessels including how constricted (closed down) or how dilated (opened up) they are. The brachial plexus nerves contain fibers by which they communicate with the sympathetic nervous system. Therefore, when the nerves are compressed, these fibers are compressed and can cause the sympathetic nervous system to become overactive.  Being overactive means that it can tell the vessels to overconstrict which reduces blood flow resulting in coldness and/or blue/purple/mottled discoloration. It can also tell them to open too wide resulting in swelling, redness, bulging veins, etc. Arm elevation and arm hanging down positioning further irritates the nerves by either compressing them more or stretching them which can enhance these vasoconstriction symptoms.


elbow pain
wrist pain
bottom of page